CN105339743A - Turbo refrigerator - Google Patents

Abstract

A turbo refrigerator (1) comprising: a turbo compressor (5) having an electric motor (10); and an oil cooling unit (7) cooling at least part of lubricating oil supplied to the turbo compressor (5), Among them, the turbo refrigerator (1) has: a refrigerant introduction part (T), which introduces a part of the refrigerant circulating in the evaporator (4) and the condenser (2) into the motor accommodation space (S3) and an inside of the oil cooling unit (7); and a cooling unit (8) for cooling the refrigerant introduced into the housing space (S3) of the motor and the inside of the oil cooling unit (7).

Description

turbo freezer

technical field

The present invention relates to turbo refrigerators.

This application claims priority based on Japanese Patent Application No. 2013-117736 for which it applied in Japan on June 4, 2013, and uses the content here.

Background technique

In a turbo refrigerator having a turbo compressor driven by a motor, for example, the motor is cooled by supplying a part of the refrigerant circulating through the evaporator and the condenser to the motor (for example, refer to Patent Document 1). In addition, in the turbo refrigerator disclosed in Patent Document 1, lubricating oil is always supplied to the gears and the like connecting the rotating shaft of the motor and the impeller, and the lubricating oil is cooled by the heat exchanger with the refrigerant and then supplied to the gears. and so on to cool the gears, etc.

Patent Document 2 discloses a technique of integrating an intercooler and a motor for driving a turbo compressor. part of the liquefied refrigerant.

Patent Document 3 discloses a pressure equalizing pipe that connects an oil tank that stores lubricating oil and a compression mechanism that is provided with a suction capacity that controls the capacity of the refrigerant passing through the turbo compressor. Space for the control section (inlet guide vane) and the low-stage compression section and high-stage compression section of the turbo compressor.

prior art literature

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2007-212112

Patent Document 2: Japanese Patent Laid-Open No. 2001-349628

Patent Document 3: Japanese Patent Laid-Open No. 2009-186029

Contents of the invention

The problem to be solved by the invention

As is well known, a turbo refrigerator is a type of heat pump, and in recent years, it has been proposed to use such a turbo refrigerator in a higher temperature range than before in order to obtain high-temperature hot water. For example, in a conventional turbo refrigerator, the temperature of the refrigerant in the evaporator with the lowest temperature is about several degrees Celsius. However, in a turbo refrigerator used in a high temperature range as described above, the refrigerant in the evaporator The temperature is about tens of degrees Celsius, and the condenser becomes even higher temperature. Therefore, there is a possibility that the motor and lubricating oil cannot be sufficiently cooled.

The present invention has been made in view of the above circumstances, and an object of the present invention is to sufficiently cool a motor and lubricating oil in a turbo refrigerator.

means to solve the problem

A first aspect of the present invention is a turbo refrigerator including: a turbo compressor having a motor; and an oil cooling unit cooling at least part of the lubricating oil supplied to the turbo compressor. The machine has: a refrigerant introduction part that introduces part of the refrigerant circulating in the evaporator and condenser into the housing space of the motor and the inside of the oil cooling part; The refrigerant inside the storage space and the oil cooling unit is a compressor that cools the storage space introduced into the motor by decompressing the storage space of the motor and the inside of the oil cooling unit. space and the inside of the oil cooling unit, recover the refrigerant from the housing space of the motor and the inside of the oil cooling unit, and return the refrigerant to the evaporator.

A second aspect of the present invention is the first aspect, further comprising an oil return portion that returns the lubricating oil stored in the housing space of the motor to an oil tank storing the lubricating oil.

A third aspect of the present invention is the second aspect, wherein the oil return unit is a displacer, and the displacer moves the lubricating oil using compressed refrigerant gas generated by the turbo compressor.

A fourth aspect of the present invention, in any one of the above-mentioned first to third aspects, includes: a bearing that pivotally supports the rotating shaft of the motor; a first non-contact sealing mechanism and a second non-contact sealing mechanism disposed on a position closer to the rotor side of the motor than the bearing, and arranged along the axial direction of the rotating shaft; and a compressed gas supply part that supplies the Part of the compressed refrigerant gas produced by the turbo compressor.

A fifth aspect of the present invention is the above-mentioned first aspect, wherein the cooling unit has a sub-refrigerator, and the sub-refrigerator cools the refrigerant introduced into the motor and the oil cooling unit.

Invention effect

According to the present invention, the refrigerant introduced into the housing space of the motor and the oil cooling unit is cooled by the cooling unit. Therefore, according to the present invention, even when the temperature of the refrigerant in the condenser is not sufficiently low, the temperature of the refrigerant can be lowered by the cooling unit, and the motor and lubricating oil can be sufficiently cooled.

Description of drawings

Fig. 1 is a system diagram of a turbo refrigerator in a first embodiment of the present invention.

Fig. 2 is a system diagram of a turbo refrigerator in a second embodiment of the present invention.

detailed description

Hereinafter, one embodiment of the turbo refrigerator according to the present invention will be described with reference to the drawings. In addition, in the following drawings, the scale of each member is appropriately changed so that each member has a recognizable size.

(first embodiment)

FIG. 1 is a system diagram of a turbo refrigerator 1 in the first embodiment of the present invention. As shown in FIG. 1 , a turbo refrigerator 1 includes a condenser 2, an economizer (economizer) 3, an evaporator 4, a turbo compressor 5, an expansion valve 6, an oil cooler 7 (oil cooling unit), and a small compressor 8 ( cooling part), and the discharger 9 (oil return part).

The condenser 2 is connected to the discharge pipe 5a of the turbo compressor 5 via the flow path R1. The refrigerant (compressed refrigerant gas X1 ) compressed by the turbo compressor 5 is supplied to the condenser 2 through the flow path R1 . The condenser 2 liquefies the compressed refrigerant gas X1. The condenser 2 has heat transfer tubes 2a through which cooling water flows, and cools and liquefies the compressed refrigerant gas X1 through heat exchange between the compressed refrigerant gas X1 and the cooling water. In addition, as such a refrigerant, Freon or the like can be used.

The compressed refrigerant gas X1 is cooled and liquefied by heat exchange with cooling water to become a refrigerant liquid X2, which remains at the bottom of the condenser 2 . The bottom of the condenser 2 is connected to an economizer 3 via a flow path R2. In addition, an expansion valve 6 (first expansion valve 61 ) for reducing the pressure of the refrigerant liquid X2 is provided in the flow path R2. The refrigerant liquid X2 decompressed by the first expansion valve 61 is supplied to the economizer 3 through the flow path R2.

The economizer 3 temporarily stores the decompressed refrigerant liquid X2, and separates the refrigerant into a liquid phase and a gas phase. The top of the economizer 3 is connected to the economizer connection pipe 5b of the turbo compressor 5 via the flow path R3. The gas-phase component X3 of the refrigerant separated by the economizer 3 is supplied to the second compression stage 12 described later through the flow path R3 without passing through the evaporator 4 and the first compression stage 11 described later, thereby improving turbo compression. Machine 5 efficiency. On the other hand, the bottom of the economizer 3 is connected to the evaporator 4 via the flow path R4. An expansion valve 6 (second expansion valve 62 ) for further reducing the pressure of the refrigerant liquid X2 is provided in the flow path R4 . The refrigerant liquid X2 decompressed further by the second expansion valve 62 is supplied to the evaporator 4 through the flow path R4.

The evaporator 4 evaporates the refrigerant liquid X2 and cools cold water using the heat of vaporization.

The evaporator 4 has heat transfer tubes 4 a through which cold water flows, and cools the cold water and evaporates the refrigerant liquid X2 through heat exchange between the refrigerant liquid X2 and the cold water. The refrigerant liquid X2 absorbs heat through heat exchange with cold water, and evaporates into refrigerant gas X4. The top of the evaporator 4 is connected to the suction pipe 5c of the turbo compressor 5 via a flow path R5. The refrigerant gas X4 evaporated in the evaporator 4 is supplied to the turbo compressor 5 through the flow path R5.

The turbo compressor 5 compresses the evaporated refrigerant gas X4 and supplies it to the condenser 2 as compressed refrigerant gas X1. The turbo compressor 5 is a two-stage compressor including a first compression stage 11 for compressing the refrigerant gas X4 and a second compression stage 12 for further compressing the one-stage compressed refrigerant.

An impeller 13 is provided in the first compression stage 11 , and an impeller 14 is provided in the second compression stage 12 , and they are connected by a rotating shaft 15 . The turbo compressor 5 has a motor 10, and the motor 10 rotates the impeller 13 and the impeller 14 to compress the refrigerant. The impeller 13 and the impeller 14 are radial impellers, and guide the refrigerant sucked in the axial direction along the radial direction.

An inlet guide vane 16 for adjusting the suction amount of the first compression stage 11 is provided on the suction pipe 5c. The inlet guide vane 16 is rotatable so that the apparent area viewed from the flow direction of the refrigerant gas X4 can be changed. A diffuser flow path is respectively provided around the impeller 13 and the impeller 14 , and the refrigerant guided out in the radial direction is compressed and boosted in the diffuser flow path. In addition, the refrigerant can be supplied to the next compression stage through the scroll flow path provided around the diffuser flow path. A meter-out valve 17 is provided around the impeller 14, and the meter-out valve 17 can control the discharge amount from the exhaust pipe 5a.

In addition, the turbo compressor 5 has a hermetically sealed housing 20 . The inside of the housing 20 is divided into a compression flow passage space S1, a first bearing storage space S2, a motor storage space S3, a gear unit storage space S4, a second bearing storage space S5, a first compressed gas supply space S6, and a second compressed air supply space S6. Compressed gas is supplied to the space S7.

The impeller 13 and the impeller 14 are provided in the compression channel space S1. The rotary shaft 15 connecting the impeller 13 and the impeller 14 is provided so as to be inserted through the compression flow path space S1, the first bearing accommodating space S2, and the gear unit accommodating space S4. A bearing 21 for supporting the rotary shaft 15 is provided in the first bearing accommodation space S2.

A stator 22 , a rotor 23 , and a rotating shaft 24 connected to the rotor 23 are provided in the motor housing space S3 . The rotating shaft 24 is provided so as to be inserted through the motor housing space S3, the gear unit housing space S4, the second bearing housing space S5, the first compressed gas supply space S6, and the second compressed gas supply space S7. The bearing 31 which supports the non-load side of the rotating shaft 24 is provided in the 2nd bearing accommodation space S5. A gear unit 25 , a bearing 26 and a bearing 27 , and an oil tank 28 are provided in the gear unit accommodation space S4 .

The gear unit 25 has a large-diameter gear 29 fixed to the rotating shaft 24 , and a small-diameter gear 30 fixed to the rotating shaft 15 and meshing with the large-diameter gear 29 . The gear unit 25 transmits the rotational force in such a manner that the rotational speed of the rotational shaft 15 is increased (accelerated) relative to the rotational speed of the rotational shaft 24 . The bearing 26 supports the rotary shaft 24 . The bearing 27 supports the rotary shaft 15 . The oil tank 28 stores lubricating oil supplied to each sliding portion such as the bearing 21 , the bearing 26 , the bearing 27 , and the bearing 31 .

The first compressed gas supply space S6 is provided between the motor housing space S3 and the gear unit housing space S4. The second compressed gas supply space S7 is provided between the motor housing space S3 and the second bearing housing space S5. The first compressed gas supply space S6 and the second compressed gas supply space S7 are connected to a flow path R13 described later, and the compressed refrigerant gas X1 is supplied through the flow path R13.

In such a housing 20, a sealing mechanism 32 and a sealing mechanism 33 for sealing the periphery of the rotating shaft 15 are provided between the compression flow path space S1 and the first bearing housing space S2. In addition, in the housing 20, a sealing mechanism 34 for sealing the periphery of the rotating shaft 15 is provided between the compression flow path space S1 and the gear unit housing space S4. In addition, in the housing 20, a sealing mechanism 35 for sealing the periphery of the rotating shaft 24 is provided between the gear unit housing space S4 and the first compressed gas supply space S6. Moreover, in the frame body 20, the sealing mechanism 36 which seals the periphery of the rotating shaft 24 is provided between the 2nd bearing accommodation space S5 and the 2nd compressed gas supply space S7. Moreover, in the housing 20, the sealing mechanism 38 which seals the periphery of the rotating shaft 24 is provided between the motor accommodation space S3 and the 1st compressed gas supply space S6. In addition, in the housing 20, a sealing mechanism 39 for sealing the periphery of the rotating shaft 24 is provided between the motor housing space S3 and the second compressed gas supply space S7.

The sealing mechanism 32, the sealing mechanism 33, the sealing mechanism 34, the sealing mechanism 35, the sealing mechanism 36, the sealing mechanism 38, and the sealing mechanism 39 are non-contact sealing mechanisms that perform sealing in a non-contact manner, and are composed of, for example, a sealing mechanism having a labyrinth structure. . Among them, the sealing mechanism 35 disposed between the gear unit housing space S4 and the first compressed gas supply space S6, and the sealing mechanism 38 disposed between the motor housing space S3 and the first compressed gas supply space S6 correspond to the present invention. The first non-contact sealing mechanism and the second non-contact sealing mechanism. That is, the sealing mechanism 35 and the sealing mechanism 38 function as a first non-contact sealing mechanism and a second non-contact sealing mechanism, wherein the first non-contact sealing mechanism and the second non-contact sealing mechanism are arranged closer to the motor 10 than the bearing 26 position on the rotor 23 side, and are aligned along the axial direction of the rotating shaft 24 . In addition, the sealing mechanism 36 disposed between the second bearing housing space S5 and the second compressed gas supply space S7 and the sealing mechanism 39 disposed between the motor housing space S3 and the second compressed gas supply space S7 also correspond to The first non-contact sealing mechanism and the second non-contact sealing mechanism of the present invention.

The motor housing space S3 is connected to the condenser 2 via the flow path R6. An expansion valve 6 (third expansion valve 63 ) is provided in front of the motor housing space S3 in the flow path R6 . The refrigerant gas X5 generated by depressurizing the refrigerant liquid X2 taken out from the condenser 2 by the third expansion valve 63 is supplied to the motor housing space S3 . The refrigerant gas X5 supplied to the motor housing space S3 cools the motor 10 housed in the motor housing space S3 . In addition, the flow path R6 is branched and connected to the oil cooler 7 . An expansion valve 6 (fourth expansion valve 64 ) is provided in front of the oil cooler 7 in the flow path R6 .

The flow path R6 described above functions as the refrigerant introduction part T of the present invention, and the refrigerant introduction part T of the present invention introduces a part of the refrigerant circulating in the evaporator 4 and the condenser 2 into the motor housing space S3 and the oil cooling unit. inside of device 7. Furthermore, the third expansion valve 63 and the fourth expansion valve 64 adjust the pressure of the motor housing space S3 and the saturated pressure inside the oil cooler 7 , thereby adjusting the temperature of the motor housing space S3 and the temperature of the oil cooler 7 .

An oil supply pump 37 is arranged in the oil tank 28 . The oil supply pump 37 is connected to the second bearing accommodating space S5 via, for example, a flow path R8. Lubricating oil is supplied from the oil tank 28 to the second bearing accommodation space S5 through the flow path R8. The lubricating oil supplied to the second bearing accommodating space S5 is supplied to the bearing 31 to ensure the lubricity of the sliding portion of the rotating shaft 24 and suppress (cool) heat generation at the sliding portion. The second bearing accommodation space S5 is connected to the oil tank 28 via the flow path R9. The lubricating oil supplied to the second bearing housing space S5 returns to the oil tank 28 through the flow path R9. In addition, the flow path R8 is also connected to the first bearing accommodating space S2 and the gear unit accommodating space S4 , and also supplies lubricating oil to the bearing 21 , the gear unit 25 , the bearing 26 , and the bearing 27 . In addition, the lubricating oil supplied to the first bearing accommodating space S2 and the gear unit accommodating space S4 returns to the oil tank 28 through the flow path inside the housing 20 .

The oil cooler 7 is provided in the middle of the flow path R8. The inside of the oil cooler 7 is supplied with a refrigerant gas X6 generated by decompressing the refrigerant liquid X2 taken out from the condenser 2 by the fourth expansion valve 64 . Such an oil cooler 7 cools the lubricating oil supplied to the turbo compressor 5 by exchanging heat between the lubricating oil flowing through the flow path R8 and the refrigerant gas X6 supplied through the flow path R6 .

The small compressor 8 is smaller than the turbo compressor 5, and is connected to the motor housing space S3 via the flow path R10. The small compressor 8 decompresses the motor housing space S3 so that the temperature of the refrigerant gas X5 introduced into the motor housing space S3 becomes a temperature suitable for cooling the motor 10 . That is, in the present embodiment, the small compressor 8 cools the refrigerant gas X5 supplied to the motor housing space S3. In addition, the small compressor 8 recovers the refrigerant gas X5 from the motor housing space S3 through the flow path R10 and returns the refrigerant gas X5 to the evaporator 4 through the flow path R11 .

In addition, the small compressor 8 is connected to the oil cooler 7 through the flow path R12, and depressurizes the inside of the oil cooler 7 of the refrigerant gas X6 supplied to the oil cooler 7 so that the refrigerant gas X6 introduced into the oil cooler 7 The temperature of the refrigerant gas X6 becomes a temperature suitable for cooling lubricating oil. That is, in the present embodiment, the small compressor 8 cools the refrigerant gas X6 supplied into the oil cooler 7 . In addition, the small compressor 8 recovers the refrigerant gas X6 from the inside of the oil cooler 7 through the flow path R12 and returns the refrigerant gas X6 to the evaporator 4 through the flow path R11 .

In addition, in the turbo refrigerator 1 of the present embodiment, the first compressed gas supply space S6 and the second compressed gas supply space S7 are connected to the compressed flow path space S1 via the flow path R13 (compressed gas supply portion). This flow path R13 supplies a part of the compressed refrigerant gas X1 generated by the turbo compressor 5 to the first compressed gas supply space S6 and the second compressed gas supply space S7 . In this way, by supplying the compressed refrigerant gas X1 to the first compressed gas supply space S6 and the second compressed gas supply space S7, compressed refrigeration is supplied between the sealing mechanism 35 and the sealing mechanism 38 and between the sealing mechanism 36 and the sealing mechanism 39. Agent gas X1. That is, in the present embodiment, the flow path R13 functions as a compressed gas supply unit, and the compressed gas supply unit supplies the first non-contact sealing mechanism (sealing mechanism 35 and sealing mechanism 36) and the second non-contact sealing mechanism (sealing mechanism 38). A part of the compressed refrigerant gas generated by the turbo compressor 5 is supplied between the sealing mechanism 39 ). In addition, a flow rate adjustment valve 40 is provided in the middle of the flow path R13, and the flow rate of the compressed refrigerant gas supplied to the first compressed gas supply space S6 and the second compressed gas supply space S7 can be adjusted.

The ejector 9 (oil return portion) is provided in the middle of the flow path R14 connecting the compressed flow path space S1 to the oil tank 28, and is connected to the bottom of the motor housing space S3 via the flow path R15. The ejector 9 moves the lubricating oil remaining in the bottom of the motor housing space S3 to the oil tank 28 via the flow path R15 by utilizing the static pressure of the compressed refrigerant gas X1 flowing in the flow path R14. Such a discharger 9 functions as an oil return part of the present invention that returns the lubricating oil remaining in the motor housing space S3 to the oil tank storing the lubricating oil.

In the turbo refrigerator 1 of the present embodiment having such a structure, the compressed refrigerant gas X1 is cooled and condensed by the cooling water in the condenser 2, and heat is released by heating the cooling water. The refrigerant liquid X2 generated by condensation in the condenser 2 is decompressed by the first expansion valve 61 and supplied to the economizer 3 , and after the gas phase component X3 is separated, it is further decompressed by the second expansion valve 62 and supplied to the economizer 3 . Evaporator4. In addition, the gas phase component X3 is supplied to the turbo compressor 5 via the flow path R3.

The refrigerant liquid X2 supplied to the evaporator 4 evaporates in the evaporator 4 and absorbs the heat of the cold water to cool the cold water. Thereby, the heat of the cold water before being cooled substantially is transferred to the cooling water supplied to the condenser 2 . The refrigerant gas X4 generated by evaporating the refrigerant liquid X2 is supplied to the turbo compressor 5 to be compressed, and then supplied to the condenser 2 again.

In addition, part of the refrigerant liquid X2 remaining in the condenser 2 is supplied to the motor housing space S3 and the oil cooler 7 via the flow path R6. The interior of the motor housing space S3 and the oil cooler 7 is decompressed by the small compressor 8 . Therefore, the refrigerant liquid X2 introduced into the motor housing space S3 through the flow path R6 passes through the third expansion valve 63 to become a refrigerant gas X5 and is cooled to a temperature suitable for cooling the motor 10 . As a result, the motor 10 is sufficiently cooled. In addition, the refrigerant liquid X2 introduced into the oil cooler 7 through the flow path R6 becomes the refrigerant gas X6 through the fourth expansion valve 64 and is cooled to a temperature suitable for cooling lubricating oil. As a result, the lubricating oil flowing through the flow path R8 is sufficiently cooled inside the oil cooler 7 . In this way, the refrigerant gas X5 that has cooled the motor 10 and the refrigerant gas X6 that has cooled the lubricating oil are sucked into the small compressor 8 to be recovered, and returned to the evaporator 4 through the flow path R11 .

In addition, the lubricating oil flowing through the flow path R8 is supplied to the first bearing accommodating space S2, the second bearing accommodating space S5, and the gear unit accommodating space S4 to reduce the sliding resistance of the bearing 21 and the gear unit 25, etc., and also to the bearings. 21 and the gear unit 25 etc. for cooling.

In addition, the compressed refrigerant gas X1 generated by the turbo compressor 5 is supplied to the first compressed gas supply space S6 and the second compressed gas supply space S7 through the flow path R13. In this way, the compressed refrigerant gas X1 is supplied to the first compressed gas supply space S6 and the second compressed gas supply space S7, and the compressed refrigerant is supplied between the sealing mechanism 35 and the sealing mechanism 38 and between the sealing mechanism 36 and the sealing mechanism 39. Gas X1. By supplying the compressed refrigerant gas X1, the internal pressures of the first compressed gas supply space S6 and the second compressed gas supply space S7 are higher than those of the gear unit housing space S4 and the second bearing housing space S5. As a result, the lubricating oil supplied to the gear unit housing space S4 and the second bearing housing space S5 is less likely to enter the first compressed gas supply space S6 and the second compressed gas supply space through the minute gap between the sealing mechanism 35 and the sealing mechanism 36. S7.

In addition, a part of the compressed refrigerant gas X1 flowing in the compressed flow path space S1 is supplied to the oil tank 28 having an internal pressure lower than that of the compressed flow path space S1 through the flow path R14 . The lubricating oil remaining in the motor housing space S3 is sucked and moved toward the oil tank 28 by the ejector 9 provided in the middle of the flow path R14 .

According to the turbo refrigerator 1 of the present embodiment as described above, the refrigerant gas X5 introduced into the motor housing space S3 and the refrigerant gas X6 introduced into the oil cooler 7 are cooled by the small compressor 8 . Therefore, according to the turbo refrigerator 1 of the present embodiment, even when the temperature of the refrigerant liquid X2 in the condenser 2 is not sufficiently low, the temperature of the refrigerant can be lowered by the small compressor 8 and the temperature of the refrigerant can be sufficiently reduced. Cool down the motor 10 and lubricating oil.

In addition, according to the turbo refrigerator 1 of the present embodiment, the temperature of the refrigerant gas X6 is lowered using the small compressor 8 . Therefore, the temperature of the refrigerant can be lowered with a simple structure, and the motor 10 and the lubricating oil can be sufficiently cooled.

Moreover, according to the turbo refrigerator 1 of this embodiment, the discharger 9 which returns the lubricating oil remaining in the motor housing space S3 to the oil tank 28 which stores lubricating oil is provided. In this embodiment, since the motor accommodating space S3 is decompressed by the small compressor 8, lubricating oil easily flows into the motor accommodating space S3 from the gear unit accommodating space S4 and the second bearing accommodating space S5. On the other hand, by providing the above-mentioned ejector 9, the lubricating oil accumulated in the motor housing space S3 can be discharged and returned to the oil tank 28, and the reduction of the lubricating oil can be suppressed.

In addition, although the lubricating oil remaining in the motor accommodating space S3 can be discharged by a pump, in this case, if the lubricating oil does not remain in the motor accommodating space S3, there is a problem such as the pump idling. On the other hand, by discharging the lubricating oil from the motor accommodating space S3 using the ejector 9 , troubles can be avoided even when the lubricating oil does not remain in the motor accommodating space S3 .

In addition, according to the turbo refrigerator 1 of the present embodiment, the compressed refrigerant gas X1 is supplied between the sealing mechanism 35 and the sealing mechanism 38 and between the sealing mechanism 36 and the sealing mechanism 39 . As a result, the lubricating oil supplied to the gear unit housing space S4 and the second bearing housing space S5 is less likely to enter the first compressed gas supply space S6 and the second compressed gas supply space through the minute gap between the sealing mechanism 35 and the sealing mechanism 36. S7. Thus, according to the turbo refrigerator 1 of the present embodiment, it is possible to suppress a decrease in lubricating oil and the like.

(second embodiment)

Next, a second embodiment of the present invention will be described. In addition, in the description of this embodiment, the description of the same parts as those of the above-mentioned first embodiment will be omitted or simplified.

Fig. 2 is a system diagram of a turbo refrigerator 1A in a second embodiment of the present invention. As shown in the figure, the turbo refrigerator 1A of the present embodiment is not provided with the flow path R10 , flow path R11 , flow path R12 , flow path R13 , and flow path R14 of the turbo refrigerator 1A of the first embodiment described above. , flow path R16, small compressor 8, discharger 9, sealing mechanism 38, sealing mechanism 39, third expansion valve 63, fourth expansion valve 64, flow rate adjustment valve 40, first compressed gas supply space S6 and second compression gas Gas supply space S7.

In this embodiment, the first port 65 is provided instead of the third expansion valve 63 , and the second port 66 is provided instead of the fourth expansion valve 64 . In the present embodiment, the refrigerant liquid X2 flowing through the flow path R6 is depressurized by the first port 65 while being kept in a liquid state, and supplied to the motor housing space S3.

In addition, the refrigerant liquid X2 flowing through the flow path R6 is depressurized by the second port 66 while being kept in a liquid state, passed through the oil cooler 7 , and then supplied to the motor housing space S3 . In addition, the refrigerant liquid X2 cools the motor 10 through a flow path (not shown) formed around the motor 10, and is discharged from the motor housing space S3. The motor accommodation space S3 is connected with a flow path R16 connected to the evaporator 4, and the refrigerant liquid X2 returns to the evaporator 4 through the flow path R16.

As shown in FIG. 2 , the turbo refrigerator 1 according to the present embodiment has a small refrigerator 51 (sub-refrigerator) provided in the middle of the flow path R6. This small refrigerator 51 has a small condenser 52 , a small evaporator 53 , and a small compressor 54 . In addition, the small refrigerator 51 has an expansion valve (not shown) between the small condenser 52 and the small evaporator 53 . Such a compact refrigerator 51 cools only the refrigerant liquid X2 flowing in the flow path R6. Therefore, the small condenser 52 , the small evaporator 53 , and the small compressor 54 are extremely smaller than the condenser 2 , the evaporator 4 , and the turbo compressor 5 .

Also in this embodiment, the flow path R6 is made to function as the refrigerant introduction part T of the present invention, and the refrigerant introduction part T of the present invention introduces a part of the refrigerant circulating in the evaporator 4 and the condenser 2. To the inside of the motor housing space S3 and the oil cooler 7.

In the turbo refrigerator 1A of the present embodiment having such a structure, the refrigerant liquid X2 introduced into the motor housing space S3 and the oil cooler 7 is cooled by the compact refrigerator 51 . Therefore, according to the turbo refrigerator 1A of the present embodiment, even when the temperature of the refrigerant liquid X2 in the condenser 2 is not sufficiently low, it is possible to sufficiently cool the motor 10 and the lubricating oil.

As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. The various shapes, combinations, etc. of the components shown in the above-mentioned embodiments are examples, and various changes can be made based on design requirements and the like within a range not departing from the gist of the present invention.

For example, in the second embodiment described above, the configuration using the first orifice 65 and the second orifice 66 has been described. However, an expansion valve may be used as in the first embodiment described above.

Industrial availability

According to the present invention, the motor and lubricating oil can be sufficiently cooled in the turbo refrigerator.

Label description

1. 1A: turbo refrigerator; 2: condenser; 2a: heat transfer tube; 3: economizer; 4: evaporator; 4a: heat transfer tube; 5: turbo compressor; 5a: exhaust pipe; 5b: energy saving 5c: suction pipe; 6: expansion valve; 7: oil cooler (oil cooling part); 8: small compressor (cooling part); 9: refrigerant; 10: motor; 11: first compressor stage; 12: second compression stage; 13, 14: impeller; 15: rotating shaft; 16: inlet guide vane; 17: outlet throttle valve; 20: frame; 21: bearing; 22: stator; 23: rotor ;24: rotating shaft; 25: gear unit; 26, 27: bearing; 28: fuel tank; 29: large diameter gear; 30: small diameter gear; 31: bearing; 32, 33, 34: sealing mechanism; 35, 36: sealing mechanism (the first non-contact sealing mechanism); 37: oil supply pump; 38, 39: sealing mechanism (the second non-contact sealing mechanism); 40: flow adjustment valve; 51: small refrigerator (cooling unit, auxiliary refrigerator); 52: small condenser; 53: small evaporator; 54: small compressor; 61: 1st expansion valve; 62: 2nd expansion valve; 63: 3rd expansion valve; 64: 4th expansion valve; 65: 1st Orifice; 66: 2nd orifice; R1, R2, R3, R4, R5, R8, R9, R10, R11, R12, R13, R14, R15, R16: flow path; R6: flow path (refrigerant introduction part ); S1: compressed flow path space; S2: first bearing storage space; S3: motor storage space; S4: gear unit storage space; S5: second bearing storage space; S6: first compressed gas supply space; S7: second 2. Compressed gas supply space; X1: compressed refrigerant gas; X2: refrigerant liquid; X3: gas phase component; X4, X5, X6: refrigerant gas; T: refrigerant introduction part.

Claims (5)

1. A turbo refrigerator comprising: a turbo compressor having a motor; and an oil cooling unit cooling at least part of lubricating oil supplied to the turbo compressor, wherein: This turbo freezer has: a refrigerant introduction part that introduces a part of the refrigerant circulating in the evaporator and the condenser into the housing space of the motor and the inside of the oil cooling part; and a cooling unit that cools the refrigerant introduced into the housing space of the motor and the inside of the oil cooling unit, The cooling unit is a compressor that cools the oil introduced into the motor housing space and the oil cooling unit by decompressing the inside of the motor housing space and the oil cooling unit. the refrigerant inside, and recover the refrigerant from the housing space of the motor and the inside of the oil cooling unit and return the refrigerant to the evaporator. 2. The turbo refrigerator according to claim 1, wherein: The turbo refrigerator has an oil return portion that returns the lubricating oil remaining in the housing space of the motor to an oil tank that stores the lubricating oil. 3. The turbo refrigerator according to claim 2, wherein: The oil return is a displacer that moves the lubricating oil using compressed refrigerant gas generated by the turbo compressor. 4. A turbo refrigerator according to any one of claims 1 to 3, wherein: This turbo freezer has: a bearing pivotally supporting the rotating shaft of the motor; a first non-contact sealing mechanism and a second non-contact sealing mechanism arranged at a position closer to the rotor side of the motor than the bearing and aligned along the axial direction of the rotating shaft; and A compressed gas supply unit that supplies a part of the compressed refrigerant gas generated by the turbo compressor between the first non-contact sealing mechanism and the second non-contact sealing mechanism. 5. The turbo refrigerator according to claim 1, wherein: The cooling unit has a sub-refrigerator for cooling the refrigerant introduced into the motor housing space and the oil cooling unit.